Packing gland lubricator



June 5I, 1951 o. l.. GARRETSON .2,555,640

PACKING GLAND LUBRCATOR Filed Dec. 29, '1945 III-ll IN VEN TOR. O. LGARRETSON ATTORNEYS Patented `une 5, 1951 'Gwen Lil 'Garretsbn, Bartlesville, :'kla., assignor to .'Phillips sPetrolemn` Company, .a corporation of Delaware ApplicationDecember 29, 1945,"SerialNo.638;408

'3 Claims.

This invention relates'tolubrication o'ftcentri'fugal p11-mp packing glands. lIn one "of its lmore 4specific aspects it relates to ythe lubrication tof packing glands of centrifugal pumps in liquefied 'petroleumgas service.

In 'the "transfer o'f Anon-lubricating liquids "by centrifugal pumps, cthe packing gland Aassemblies of such pumps are frequently difficult to lubri- 'caterand to *maintain -in 'a fluid tight condition 'with 'respect to the 4non-'lubrica-tingliquid being pumped. Further difdcultymaybe experienced lwhen *the liquid being pumped Iis a solvent 'for -paking gland "lubricating materials.

'lha'vefound a method `for-lubricating lpumpsin liqueed petroleum gas service, which method is `broadly applicable andihasspeeial utilityon portable transportation units, v"such -as ytank itrucks. @ne 'object -iofmy invention is to `*provide `a lmeans 'for *the lubrication of1p`zatcking 4glands `of 'centrifugal pumps in :service wherein jthe liqui'd being pumped is a non-lubricating liquid `or is a solvent'for lubricants rordinarily used.

Still Yanother obj'ect'o'f my'invention is'to `provide 'a method for the lubrication of packing 'glands of centrifugalfpumps on tank trucks in liquefied petroleum gas transportation service.

Yet another `object of `my invention `isfto provide a method 'for the lubricating 'of packing "glands of centrifugaly pumps in liqueiied petroleum gas service 'and wherein `the centrifugal fpump vis powered bya'u-id motor.

' Still other objects and `advantages of my 'invention will beap'parent `tdthoseskilledin-the art i by' reference to theffollowingfdetailed descripltion and annexeddraWing'w'h-ich respectively defscribesand ill'ustrateslv-a preferred "embodiment of my invention.

The drawing illustrates 'diagram-matically'one 'form of apparatus `forf carrying out the method 'f cf-my invention.

tate 1- at a sufficientlyhigh 1YR. P. 2M. tordrive a centrifugal `pump II. `A exible coupling aIZ .serves as a .power .transmitting connection :be-`

( Cl. 'M13-87 2 tween ashaftfI 3 of ltheffluid motor and an impel-ler 'shaft -I4-o'f the centrifugal pump. The-centrifugal pump '-II has a pump volute creasing I5,.a 'stuingbox I6, Iandanimpellerll made integral '-5 -with the shaft'M.

"This centrifugal pump, for illustration purposes takes suction-through va suction line I'8-on a-tank I9 and discharges through an outlet `line 520.

` llherstuflngbox I (i contains conventional packing=rings125fa gland ?26, further packing rings 2l and a packing take -up nut4 2'8.

small diameter tube "3| Aconnects `with the tube 4 `and (-leadsfto the lower portion fof a dif- *195 ferential regulator `32. A `tube `33 "makes `fluid vc'ommuni'cati'cmI :from -the top. of -thisfdiiferential vregi'ila'tor `to the inletside of the pump-by way of theinletfor'suction line I8. A second and alternative embodiment cfthis "fluid communication "qglinvolves fa tube 3'4 vwhich is illustrated as confneeting the back or rear side ofthepump volute @with thetop portion of theregulatorby way of a iportion of'tubel'33.

'-Ihe regulator `is a diierentia'l `type instrument 25-andcontains `a diaphragm member 31, a spring V"ac'ljustment member 36 and a shut-off valve assembly-138. A tube 35 makesffluid connection from i thefpor'tion of the rregulator'belowthe diaphragm ftofthelanternvglandi26 of the pump packing.

lvhen my invention is applied Vto a tank truck adapted v@for the transportation 'of liqueed pe- `troleum gas 4the `vessel `I9 represents the truck tankandl the vcentrifugal vpump I I ,the differential zpressurezregulator #32 and the fluid motor 5 with mtheir `pipe or tube connections are mounted in close proximity `with respect toisaidtank I9. The '.fmotor I :isthe truckpower tpla'ntiand may be a Diesel Iengine or .an ordinary motor with a carburetertadaptedfor the use .of gasoline, or for .40 -theusegofiliquefedfpetroleum gas. TThis engine :indirect connection with the pump 2` when :it .is desired to operate the lcentrifugal pump 5. -Thetank :'I may :be mounted 4at any convenient rpointLon `.tl-iez'truclz. Thetubes, 6 and 8 may K45 :preferably `be flexible `tubes so that they may berable to absorb vibration without rupture. The pump 2 `may `g-preferablybe located under vthe hood inorder ito afford operating connection :between this `pump and the engine.

`When such apiece of :equipment is a tractor @.andttrailerfassembly'the flexible tubings 3, Ii` and L8 `aiord l:excellent connecting I members between .thetrailerfandtractor.

i ,Inorder .Ito-powensucha fluid fmotorgas motor 155.5, .oilpressure Lof theporder of 1500 A.,poundsper lubrication purposes.

. ted through the regulator 32.

Von the bottom of the diaphragm drops to a value 6 to the oil tank 'I.

The hydraulicrmotor is intended to rotate at suiicient speed to power in a proper manner the centrifugal pump II.

When the centrifugal pump II is in liquefied petroleum gas service it is a difficult task to prevent leakage through packing gland assembly.

- To prevent such leakage and to lubricatefthe packing members, I herein provide for the transmission of oil from reservoir I by way of the pump 2,'lines 3 and 3|, regulator 32 and tube 35 to the packing gland assembly at a pressure slightly greater than the pressure of the liquidA being pumped. The pressure differential is maintained between the. oil in tube 35 andY the liquid being pumped by adjustment of the compression spring assembly 3,6. The valve in tube 33 is open vthereby establishing fluid communication between the liquid being pumped in the suction line `Iandthe top of the diaphragm 31 in the regu- ,lator 32. For example, if the `liquid, being pumped is a liquefied petroleum gas consisting largely of liquid propane, the actual pressure-in the line I 8 may be of the order of 1,80 pounds per square inch. This pressure is communicated to the top of the diaphragm 31. When the spring Vmechanism 36 is set at 5 pounds, per square inch then the pressure necessaryVto raise the valve 39 is at least 185 pounds per square inch acting Vron the under side of the diaphragm. When this 'pressure is exactly 185l pounds per square inch then there exists a pressure differential ofv about 5 pounds tending to cause flow of oil through `tube 35 gland member 26, packing 25 and into the pump `volute I5. However, since the packing take-up nut-28 is ordinarily so adjusted as to maintain the packing assembly members in rather tight adjustment there is little actual flow of oil from tube 35 into-the pump volute I5. The main pointis to maintain a pressure differential in that direction to prevent leakage of uid being pumped'and to keep a lubricating oil in the packing gland assembly. Such an oil as is adapted to` the'operation of a pressure pumpfluid motor combination is an ideal oil for sealing and lubricating the packing gland of a centrifugal pump in sucheJ service as herein described.

As stated hereinbefore, the oil pump 2puts up' a pressureof the order of 500 pounds per square inch, and obviously such a pressure is not needed to supply sufficient :oil to the packing gland of the centrifugal pump for sealing and Even though such a pressure exists in tube3 I, itis not actually transmit- When the pressure Vand when this occurs, pressure then builds up quickly in this bottom compartment and rapidly exceeds the combined fluid pressure and spring jpressure and accordingly raises the diaphragm to close the valve 39 to further increase of pressure. This valvefoir all intents and purposes gets closed long'befo're the pressure in the lower por- 4 tion of the regulator reaches the pump 2 presa sure.

If desired the spring mechanism 36 may be so adjusted as to maintain a pressure differential of 10 pounds per square inch, or 50 pounds, or the 5 pounds as stated hereinbefore, or any pressure as deemed necessary to maintain slight oil ow from tube 35 through the` gland 2 6, packing 25 into 4the pump volutev I5.v

As mentioned hereinbefore, the equalization line from the top of the regulator 32 may be such as tube 33 connecting with the suction line I8, or may be such as tube 34 connecting with the interior of the pump volute I5 at a point on the back commercially available. Any lmaterials suitableV for the construction of the tanks and pumps, etc. in the absence of my invention may be used in conjunction with my invention as herein disclosed.V Y o Any type of differentialfregulator 32 may be used provided, of course, it performs its intended function as herein described.

Such auxiliary apparatus as Valves, and the details of the standard engine Iand pump 2 and uid motor. 3 have not been given for purposes of simplicity. Y 1 Y i n It will be obvious to those skilled inthe art that my invention` as herein disclosed has wide application, and that manymodications and yalterations therein may be made and yet remain within the intended spirit and scope of my invention. y

Having described my invention, I claim: 1. In a pumping system, a centrifugal pump lincluding an impellerhaving a shaft, an impeller housing, a shaft housing, and a packing gland between the shaft and its housing, a fluid-operated motor for rotating said shaft, a pumping system for supplying lubricating fluid at high .pressure for operating said motor, a storage bysaid shaft in said impeller housing, a system for pumping lubricating fluid inwhich theenergy imparted `to the fluid by the pump is converted into useful work, the pressure of 'said iiuid being substantially higherv than the pressure in said housing, and means for` supplying `lubricatinguid from said pumping system to saidshaft housing at a pressureslightlylhigher than .the

`.impeller housing pressure @adjacent `the shaft comprising! a storage chamber communicating with said shaft housing, a valve for controlling -the flow of` high pressure lubricating fluid vfrom jsaid'lubricating fluidV pumping system intcj'sa'id storage chamber, and 'a differential pressure regulator for said valve includ-ing means for comparing the storage chamber pressure with the sum of a fixed pressure and the mpeller housing pressure adjacent the shaft to obtain a resultant differential pressure, and a valve operating member actuated by said differential pressure.

3. In a pumping system, a centrifugal pump including an impeller having a shaft, an impeller housing, a shaft housing, and a packing gland between the shaft and its housing, a fluid-operated motor for rotating said shaft, a pumping system for supplying lubricating fluid at high pressure for operating said motor, a vessel, a diaphragm dividing said vessel into two chambers, a conduit for passing high pressure lubricating fluid from said pumping system to one of said chambers, a valve in said conduit actuated by said diaphragm, a line connecting said one chamber to said packing gland, means for communicating the impeller housing pressure to the other of said chambers, and a spring biasing said diaphragm, said spring acting in opposition to the pressure in said one chamber.

OWEN L. GARRETSON.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,841,863 Van Rijswijk Jan. 129, 1932 2,049,774 Hoffman Aug. 4, 1936 2,102,140 Ungar Dec. 14, 1937 2,107,260 Ihara Feb. 1, 1938 2,347,751 Reeves et al. May 2, 1944 2,425,885 Jennings Aug. 19, 1947 2,455,678 Jennings Dec. 7, 1948 

